A conventional mobile device often has a proximity sensor set in the display screen to detect a user's face, ears or hair, and temporarily deactivate the display screen when a close range object is detected, thereby on the one hand saving power, and on the other hand preventing the user's face and ear from accidentally touching the screen during a call and affecting the ongoing call.
For aesthetic appeal, proximity sensor apertures arranged on the mobile device are getting smaller to satisfy market demands. However, a smaller proximity sensor aperture compromises signal transmission efficiency of the transmitter inside the proximity sensor, and when the signal is not successfully transmitted out of the mobile device but reflected by the mobile device, leads to an increased crosstalk effect.
In addition, a conventional mobile device often uses a glass panel with a coated surface as a display screen, for which different color coatings or functional coatings can be selected according to user needs. However, coated glass panels have higher light transmittance and light reflectivity than uncoated glass panels or opaque panels, and therefore are associated with a stronger crosstalk effect. Such a crosstalk effect reduces the signal-to-noise ratio measured by proximity sensors, leading to inability of effectively sensing objects in proximity.